# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Deep Creek (San Bernardino County)
Water Body ID: | CAR6282000020000207135743
Water Body Type: | River & Stream

DECISION ID | 21959 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Acid Neutralizing Capacity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Acid Neutralizing Capacity (ANC) is equivalent to alkalinity, and the USEPA "Gold Book" criterion for alkalinity states that it should be greater than 20 mg/L CaCO3 unless natural alkalinity is lower. Only one ANC sample is available for Deep Creek, and it is below 20 mg/L. There is insufficient information to determine the natural range of ANC. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. It is not possible to determine whether the single sample exceeds the criterion. The minimum sample number requirements of Table 3.2 of the Listing Policy are not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21959, Acid Neutralizing Capacity | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7864
Pollutant: | Acid Neutralizing Capacity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek under the Region 6 SWAMP program. One sample collected on March 21, 2003 was analyzed for ANC. The result was 7.8 mg/L CaCO3.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no California or federal standards or criteria for acid neutralizing capacity (ANC) per se. However, ANC is equivalent to alkalinity, and the U.S. Environmental Protection Agency "Gold Book" recommends alkalinity greater than 20 mg/L CaCO3 unless natural alkalinity is lower.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | One sample was collected on March 21, 2003.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21179 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Boron
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the annual average datapoints exceeded the site-specific objective. None of the samples exceeded the drinking water criterion. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of nine samples or five annual average datapoints exceeded the applicable water quality objective and criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21179, Boron | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5127
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled boron under the Region 6 SWAMP program between 2001 and 2005. Dissolved boron concentrations in 8 of 9 samples were estimates or below the detection level. The concentration in the remaining sample was 7.4 ug/L. The objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for boron, for Station 5 in Lahontan Basin Plan Table 3-21, includes an annual average of 0.05 mg/L (or 50 ug/L) and a 90th percentile value of 0.19 mg/L (or 190 ug/L).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Nine samples (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21179, Boron | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7835
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 9
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled boron under the Region 6 SWAMP program between 2001 and 2005. Dissolved boron concentrations in 8 of 9 samples were estimates or below the detection level. The concentration in the remaining sample was 7.4 ug/L. The objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California State Notification Level criterion for boron is 1000 ug/L.
Objective/Criterion Reference: | Drinking Water Notification and Response Levels: An Overview
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Nine samples (1 to 4 samples per year) were collected between 2001 and 2005. (No samples were collected in 2002.)
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21972 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Chloride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Four out of five annual average datapoints exceed the site-specific objective. None of the samples exceed the Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 12 individual samples exceeded the California Maximum Contaminant Level. Four out of five annual average datapoints samples exceeded the site specific objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21972, Chloride | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5128
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 4
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly chloride samples under the Region 6 SWAMP program between 2001 and 2005. The range of chloride concentrations in 12 samples was 2.96 to 28.9 mg/L. The annual average objective was exceeded in 4 of 5 years.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for chloride (for Station 5 in Lahontan Basin Plan Table 3-21) includes an annual average of 9.1 mg/L and a 90th percentile value of 16.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21972, Chloride | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5129
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly chloride samples under the Region 6 SWAMP program between 2001 and 2005. The range of chloride concentrations in 12 samples was 2.96 to 28.9 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for chloride is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve samples (1 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21192 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Dissolved oxygen saturation
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. One of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. One of five samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21192, Dissolved oxygen saturation | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5814
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured percent saturation of dissolved oxygen quarterly under the Region 6 SWAMP program between April 2004 and April 2005. Percent saturation in five samples ranged from 51 to 100 percent, with one violation of the objective.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective in the Lahontan Basin Plan states that percent saturation shall not be depressed by more than 10 percent and minimum dissolved oxygen concentration shall not be less than 80 percent saturation.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Five quarterly measurements of percent saturation were taken between April 2004 and April 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22009 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Fluoride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the applicable water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 12 samples exceeded the Califonia Maximum Contaminant Level. None of 5 annual average datapoints exceeded the site-specific objective. This does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22009, Fluoride | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5224
Pollutant: | Fluoride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly fluoride samples under the Region 6 SWAMP program between 2001 and 2005. Fluoride concentrations in 12 samples were all estimates or below the detection level. The annual average objective was not violated.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for fluoride (for Station 5 in Lahontan Basin Plan Table 3-21) includes an annual average of 0.10 mg/L and a 90th percentile value of 0.19 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples (1-4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22009, Fluoride | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5225
Pollutant: | Fluoride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly fluoride samples under the Region 6 SWAMP program between 2001 and 2005. Fluoride concentrations in 12 samples were all estimates or below the detection level. The MCl was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for fluoride is 2 mg/L
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve samples (1-4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 22022 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Nitrate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the applicable water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 12 samples exceeded the California Maximum Contaminant Level. None of 5 annual average datapoints exceeded the site-specific objective. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 22022, Nitrate | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7883
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek quarterly under the Region 6 SWAMP program between 2001 and 2005. Twelve samples each were collected for nitrite and for nitrite plus nitrate. Nitrate expressed "as N" was calculated by subtraction for each sampling date. Annual average values calculated from 1 to 4 nitrate concentrations per year ranged from 0 to 0.038 mg/L "as N." When expressed "as nitrate", the annual averages ranged from 0 to 0.171 mg/L. The objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for nitrate (expressed "as nitrate") for Station 5 in Lahontan Basin Plan Table 3-21 includes an annual average of 0.2 mg/L and a 90th percentile value of 0.6 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples each (1 to 4 samples per year) were collected for nitrite and for nitrate plus nitrite between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22022, Nitrate | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7885
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek quarterly under the Region 6 SWAMP program between 2001 and 2005. Twelve samples each were collected for nitrite and for nitrite plus nitrate. Nitrate expressed "as N" was calculated by subtraction for each sampling date. Results below the detection level were treated as zeros. One sample involved an estimated result. Calculated nitrate concentrations in the remaining samples ranged from 0 to 0.076 mg/L as N. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrate is 45 mg/L "as nitrate", equivalent to 10 mg/L "as N."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples each (1 to 4 samples per year) were collected for nitrite and for nitrate plus nitrite between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21848 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 12 samples exceeded the California Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21848, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7878
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek under the Region 6 SWAMP program between 2001 and 2005. Concentrations of nitrite plus nitrate in 5 of 12 samples were below the detection level. Concentrations in the remaining samples ranged from 0.001 to 0.076 mg/L. The MCL was not violated. .
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite plus nitrate is 10 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve samples (1 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21886 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Nitrite
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 12 samples exceeded the California Maximum Contaminant Level and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21886, Nitrite | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7875
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek under the Region 6 SWAMP program between 2001 and 2005. Of 12 quarterly nitrite samples, two were estimated values and four were below the detection level. Concentrations of nitrite in the remainder were 0.001 to 0.002 mg/L. The MCL was not violated.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite is 1 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve samples (1 to 4 per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21180 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. One of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. One of eleven samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21180, Oxygen, Dissolved | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5130
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 11
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measure dissolved oxygen quarterly under the Region 6 SWAMP program between 2001 and 2005. The dissolved oxygen concentration in 11 samples ranged from 3.3 to 10.0 mg/L. There was one violation of the 4.0 minimum concentration objective.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | For waters designated for the COLD but not the SPWN beneficial use, the 1-day minimum objective is 4.0 mg/L (Lahontan Basin Plan Table 3-6).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Eleven quarterly measurements of dissolved oxygen concentration were taken between 2001 through 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21898 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Phosphate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the annual average datapoints exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of five annual average datapoints exceeded the site-specific water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21898, Phosphate | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7890
Pollutant: | Phosphate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled phosphorus under the Region 6 SWAMP program between 2002 and 2005. Reported phosphate "as P" concentrations in 10 samples ranged from below the detection level (4 samples) to 0.015 mg/L. Calculated phosphate "as phosphate" concentrations for 10 samples ranged from below the detection level to 0.046 mg/L. A single sample analyzed for "dissolved hydrolyzable P + PO4" was below the detection level. The annual average objective was not violated.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site- specific numeric objective for Deep Creek Station 5 (Lahontan Basin Plan Table 3-21) includes an annual average objective for total dissolved orthophosphate of 0.05 mg/L and a 90th percentile value of 0.13 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled (Crab Creek at Crab Flats Road near Lake Arrowhead).
Temporal Representation: | Ten quarterly samples reported "as P" were collected between 2002 and 2005 and 10 calculations for phosphate "as phosphate" were reported. A single sample, collected on 2/5/2002, was analyzed for dissolved hydrolyzable P plus PO4.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21911 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Phosphorus
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available for assessment whether any of the phosphorus samples exceed the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy due to an error in the SWAMP QAPP regarding holding times for total phosphorus samples. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. No biological data are available for use in assessment of compliance with the water quality objective for biostimulatory substances. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21911, Phosphorus | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7888
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek quarterly under the Region 6 SWAMP program between 2002 and 2005. Concentrations of total phosphorus in 3 of 9 samples were below the detection level. Concentrations in the remaining samples ranged from 0.011 to 0.069 mg/L.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan does not include a site-specific objective for total phosphorus in Deep Creek. The Basin Plan's narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Nine quarterly samples (1 to 4 samples per year) were collected between 2002 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | Sampling and analysis were done according to the SWAMP QAPP. However, in July 2009 an error was discovered in the QAPP related to holding times for total phosphorus samples that affects the validity of data for the Lahontan Region The holding time for samples that are not acid-preserved.should be 48 hours rather than 28 days as indicated in the QAPP. "Low level" phosphorus analyses, without acid preservation, are used in the Lahontan Region's SWAMP program. ..
QAPP Information Reference(s):

DECISION ID | 20985 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Specific Conductance
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 11 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20985, Specific Conductance | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5227
Pollutant: | Specific Conductance
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 11
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey took quarterly measurements of specific conductance between 2001 and 2005. Eleven laboratory measurements ranged from 53 to 226 uS/cm. Three field measurements ranged from 80 to 178 uS/cm. The MCL was not violated.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Eleven laboratory measurements and three field measurements of specific conductance were taken between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21022 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Sulfates
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of five annual average datapoints exceeded the site-specific objective. None of 12 samples exceed the California Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 5 annual average datapoints exceeded the site-specific objective. None of samples exceeded the Maximum Contaminant Level. This does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21022, Sulfates | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5228
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly sulfate samples under the Region 6 SWAMP program between 2001 and 2005. Of 12 sulfate samples, three were below detection levels. The remainder of the samples ranged from 0.1 to 2.3 mg/L. The annual average objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for sulfate (for Station 5 in Lahontan Basin Plan Table 3-21) includes an annual average of 1.3 mg/L and a 90th percentile value of 4.9 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21022, Sulfates | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5229
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly sulfate samples under the Region 6 SWAMP program between 2001 and 2005. Of 12 sulfate samples, three were below detection levels. The remainder of the samples ranged from 0.1 to 2.3 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for sulfate is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21036 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Cold Freshwater Habitat (COLD) beneficial use. The objective does not include specific numerical limits for protection of the COLD use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. One line of evidence is available to support this decision. There are not enough temperature samples to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist. Because temperature samples were collected only quarterly, weekly and monthly average data are not available for comparison with guidelines in the scientific literature for the temperature requirements of sensitive aquatic species such as salmonids, as directed in Listing Policy Section 6.1.5.9.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21036, Temperature, water | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5232
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measure water temperature quarterly under the Region 6 SWAMP program between 2001 and 2005. Temperatures in 12 measurements ranged from 2 to 17.5 degrees Celsius. The guideline was not exceeded. There are insufficient data available to define the natural temperature regime or to assess compliance with the no change requirement of the objective.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's temperature objective states: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly water temperature measurements were taken between 2001 through 2005. Sampling frequency was inadequate to characterize diel, seasonal and annual variation in temperature or to detect whether changes due to controllable factors have occurred.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21899 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Total Dissolved Solids
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the applicable water quality objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 12 samples exceeded the California Maximum Contaminant Level. Four of five annual average datapoints exceed the site-specific objective, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21899, Total Dissolved Solids | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5231
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly samples for Total Dissolved Solids (TDS) under the Region 6 SWAMP program between 2001 and 2005. The range of TDS concentrations in 12 samples was 55 to 159 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Total Dissolved Solids (TDS) is 500 mg/L..
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21899, Total Dissolved Solids | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5230
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 4
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey collected quarterly samples for Total Dissolved Solids (TDS) under the Region 6 SWAMP program between 2001 and 2005. The range of TDS concentrations in 12 samples was 55 to 159 mg/L. Annual average concentrations, based on 1 to 4 samples per year, ranged from 80 to 159 mg/L. The highest average was based on a single sample. The annual average objective was exceeded in 4 of 5 years.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for Total Dissolved Solids (for Station 5 in Lahontan Basin Plan Table 3-21) includes an annual average of 83 mg/L and a 90th percentile value of 123 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21753 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Total Kjeldahl Nitrogen (TKN)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to determine whether any of the Total Kjeldahl nitrogen samples exceed the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The chemical data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. No biological data are available for assessment of compliance with the water quality objective for biostimulatory substances. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21753, Total Kjeldahl Nitrogen (TKN) | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7877
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek quarterly under the Region 6 SWAMP program between 2001 and 2005. One of 12 quarterly samples for TKN was an estimated value. Concentrations of TKN in the remaining samples ranged from 0.09 to 0.37 mg/L. No biological data were available for assessment of compliance with the objective for biostimulatory substances.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan does not include a site-specific objective for Total Kjeldahl Nitrogen (TKN) in Deep Creek. The Basin Plan's narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples each (1 to 4 samples per year) were collected between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 21754 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | Total Nitrogen as N
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. None of 5 annual average datapoints exceeded the site-specific water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21754, Total Nitrogen as N | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 7876
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled Deep Creek quarterly under the Region 6 SWAMP program between 2001 and 2005. Twelve samples each were collected for total Kjeldahl nitrogen and nitrite plus nitrate. Eleven total nitrogen concentrations calculated from these two parameters ranged from 0.09 to 0.373 mg/L. (On one sampling date the constituents were an estimated value and a below detection level value; these were not included in the calculations.) Annual average values calculated from 1 to 4 total N concentrations per year ranged from 0.09 mg/L to 0.270 mg/L. The annual average objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for total nitrogen (for Station 5 in Lahontan Basin Plan Table 3-21) includes an annual average of 0.3 mg/L and a 90th percentile value of 0.7 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| 2007. SWAMP Data for the Mojave River Watershed
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve quarterly samples each (1 to 4 samples per year) were collected for total Kjeldahl nitrogen and nitrate plus nitrite between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):

DECISION ID | 23059 | Region 6
Deep Creek (San Bernardino County)

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: One line of evidence is available in the administrative record to assess this pollutant. For waters designated for the Cold Freshwater Habitat beneficial use, the Lahontan Basin Plan's narrative pH objective is a non-degradation objective, and sample numbers are insufficient to establish baseline conditions or detect trends as required under Listing Policy Section 3.10. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the seasonal and annual variability expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. It is not possible to determine whether the narrative pH objective was exceeded because the requirements of Listing Policy Section 3.10 were not met. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 23059, pH | Region 6
Deep Creek (San Bernardino County)
LOE ID: | 5226
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 12
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured pH under the Region 6 SWAMP program between 2001 and 2005. The range of pH in 12 measurements was 6.3 to 7.7 units. Two samples were below 6.5 but the 6.5 to 8.5 limit applies only to waters not designated for the COLD or WARM use.
Data Reference: | 2007. SWAMP Data for the Mojave River Watershed
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's pH objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, Deep Creek near Deep Creek Lake, (near the town of Arrowbear Lake) was sampled.
Temporal Representation: | Twelve pH measurements (1 to 4 per year) were taken between 2001 and 2005.
Environmental Conditions: | Deep Creek, the largest tributary of the Mojave River, has its headwaters in San Bernardino National Forest near the crest of the San Bernardino Mountains. The lower reach is impounded by the Mojave River Forks Reservoir.
QAPP Information: | The data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):